Search Results (48)

The inactivation of thrombin by antithrombin is highly enhanced by the presence of heparin chains forming “bridges” between the two proteins. X-ray structures for such ternary complexes have been published, but the molecular background of the lower efficiency of smaller heparinoids on thrombin inhibition remains poorly understood. Antithrombin-resistant prothrombin mutants (mutations affecting Arg596 in prothrombin) have been reported that cause severe thrombophilia. Our aim was to study the interactions in the antithrombin–thrombin Michaelis complex both in the presence and the absence of a heparinoid chain and in the presence of pentasaccharide by using molecular dynamics. We also intended to study the complexes of thrombin mutants as well as a known alternative antithrombin conformation at the “hinge” region built using docking. The binding between the proteins was investigated by Gaussian Accelerated Molecular Dynamics (GaMD). We compared the contribution of several amino acids at the binding “exosites” between AT and the wild type and mutant thrombins and between systems containing or not containing a heparinoid. In the docking-based simulations, several of the analyzed amino acid pairs no longer contributed to the interaction, suggesting that the open “hinge” conformation has limited biological relevance. We could identify multiple conformational types using clustering, revealing high flexibility in mutants and systems without heparinoid, probably indicating lower stability. We were also able to detect the allosteric effects of the ligands on the bound thrombin. In summary, we were able to obtain conformations using GaMD that can explain the better protein–protein interactions in the ternary complexes and the impaired AT binding of the thrombin Arg596 mutants at an atomic level. Full article

Background/Objectives: We define severe postpartum hemorrhage (PPH) with macroscopic hematuria as clinical disseminated intravascular coagulation (DIC), a life-threatening condition. We also report a methodology using machine learning, a subtype of artificial intelligence, for developing the boundary criterion for predicting hematuria on the fibrinogen–fibrin/fibrinogen degradation product (FDP) plane. A positive FDP–fibrinogen/3–60 (mg/dL) value indicates hematuria; otherwise, non-hematuria is observed. We aimed to validate this criterion using severe placental abruption (PA), and to examine the activation of the coagulation–fibrinolytic system in clinical DIC. Methods: Of 17,285 deliveries across nine perinatal centers in Japan between 2020 and 2024, 13 had severe PA without hematuria, 18 had severe PPH without hematuria, and 3 had severe PPH with hematuria, i.e., clinical DIC. We calculated the values of the criterion formula for 13 cases of severe PA to validate the boundary criterion and compared the laboratory tests for coagulation–fibrinolytic activation among the three groups. Results: The calculated values using the criterion for the 13 PA without hematuria ranged from −108.91 to −5.87 and all were negative. In cases of clinical DIC, fibrinogen levels (median, 62 mg/dL) were lower (p < 0.05), while levels of FDP (96 mg/dL), the thrombin–antithrombin complex (120 ng/mL), and the plasmin-α₂–plasmin inhibitor complex (28.4 μg/mL) were significantly higher than in the other two groups. Conclusions: This study demonstrated the validity of the boundary criterion for predicting hematuria using severe PA. The coagulation–fibrinolytic test results suggested that PPH cases with hematuria were assumed to have clinical DIC, indicating that this criterion may be considered for diagnosing DIC during delivery. However, further additional patient data are needed to confirm the usefulness of this criterion because of the very low number of hematuria cases. Full article

Background/Objectives: Medical leech (Hirudo in the Chinese Pharmacopoeia) is renowned in traditional medicine for its significant antithrombin activity. As an animal-derived medicine with complex and incompletely understood composition, its insufficient quality control measures are met with widespread counterfeiting caused by limited animal resources and rising demand. Methods: In this study, an integrated quality evaluation strategy guided by “Totality of the Evidence” (TOE) method is proposed. This strategy combines chemical characterization of small and macromolecular components with bioassays relevant to its clinical functions. A total of 28 batches of samples were analyzed, comprising 23 genuine and 5 counterfeit batches. Species origins were identified by morphology and DNA barcoding. Chemical characterization included TLC, HPLC and UPLC-QTOF-MS/MS for small molecules, and SDS-PAGE with HPLC-Orbitrap Fusion Lumos Tribrid-MS for macromolecules. Antithrombotic activity was assessed by thrombin titration and platelet aggregation assays. Results: Several characteristic components were discovered and identified as key quality control markers, including eight small molecules such as an unreported compound SZ-1, plus seven major differential proteins across species. Based on these markers, accurate and rapid authentication methods were established using SDS-PAGE for macromolecules, and both HPLC and TLC for small molecules. Furthermore, using bioassay methods we established for quality evaluation, Hirudo nipponica exhibits potent anti-thrombin activity and inhibits platelet aggregation, while Whitmania pigra shows weak anti-thrombin activity and promotes platelet aggregation. Conclusions: This quality evaluation strategy is not only applicable for the quality assessment of genuine Hirudo products of different origins, but also for distinguishing medical leeches from their counterfeits. Full article

(1) Background: The hemostatic system and tumor biology display a tight and reciprocal interaction where clotting products enhance tumor growth and dissemination, and the tumor, in turn, triggers a hypercoagulable and inflammatory state. Evaluating circulating biomarkers related to thrombo-inflammatory may provide a promising tool for predicting tumor outcomes, especially in non-small cell lung cancer (NSCLC) characterized by unfavorable outcomes. (2) Aim: In a prospective cohort of NSCLC patients, we evaluated whether thromboinflammatory biomarkers could predict early disease progression (DP) during the first 6 months of first-line anticancer treatment. (3) Methods: 719 newly diagnosed advanced-stage NSCLC patients were included. Complete blood cell count, high-sensitivity C-reactive protein (hs-CRP), FVIII, fibrinogen, D-dimer, thrombin-antithrombin (TAT) complexes, and prothrombin fragment1+2(F1+2) were tested in blood samples collected before starting chemotherapy. DP was gathered during follow-up. (4) Results: The 6-month cumulative incidence rate for DP was 49%. Univariable Cox regression analysis identified metastatic status, BMI, hemoglobin, leukocytes, hs-CRP, FVIII, fibrinogen, TAT, and D-dimer as significant predictors of DP. In a multivariable analysis that included all previously significant variables, only hs-CRP and D-Dimer levels remained strongly associated with DP. The two variables were used to establish a risk stratification model that significantly identified patients at high risk of DP at 6 months (HR 2.9; 95% CI, 2.3–3.7), which can be applied to 3, 9, and 12 months. (5) Conclusions: Our model easily and precisely estimates early DP during chemotherapy. If externally validated, this model can significantly enhance the allocation of medical resources in managing advanced NSCLC, ensuring that patients receive the most effective care possible. Full article

Preterm birth and low birth weight remain major contributors to neonatal morbidity and mortality, yet the underlying mechanisms are not fully understood. Maternal microbiota has been implicated in adverse pregnancy outcomes, but key mediators remain unidentified. We previously showed that the microbiota-derived peptide corisin induces epithelial apoptosis via mitochondrial membrane depolarization and reactive oxygen species accumulation. In this retrospective preliminary study, we evaluated the association between maternal serum corisin levels and pregnancy outcomes in 84 eligible women. Among them, 10 experienced preterm birth, and 22 delivered low-birth-weight infants. Corisin levels were significantly elevated in these groups compared with women with full-term, normal-weight deliveries. Preterm birth was associated with increased tissue factor, while low birth weight correlated with higher thrombin–antithrombin complex and soluble thrombomodulin and lower fibrinogen levels. Corisin concentrations showed negative correlations with maternal BMI, birth weight and length, and estimated fetal weight. Positive correlations were observed between corisin, myeloperoxidase, and several coagulation markers. These preliminary findings suggest that elevated maternal corisin levels are associated with adverse pregnancy outcomes and may reflect underlying mechanisms involving oxidative stress and coagulation activation. Further investigation is warranted to clarify its potential role as a microbiota-derived biomarker in pregnancy complications. Full article

Little is known about the effect of hepatic hemangiomas on protein induced by vitamin K absence or antagonist II (PIVKA-II). The aim of this study was to clarify the correlation of PIVKA-II levels with hepatic hemangiomas. In 335 consecutive patients with hepatic hemangiomas, ultrasonography (US), laboratory tests for liver function, serum levels of PIVKA-II and α-fetoprotein (AFP), and coagulation factors (platelets, prothrombin time (PT), fibrinogen, thrombin–antithrombin III complex (TAT), D-dimer, and fibrin and fibrinogen degradation products (FDPs)) as indicators of coagulation disorders were examined. PIVKA-II levels were significantly higher in the hemangioma group than in the control group (p < 0.0001), and significantly higher in the large hemangioma group (p < 0.0001). PIVKA-II levels in the hemangioma increase group were higher with increases in tumor size and abnormal coagulation factors, and those in the hemangioma decrease group were lower with decreases in tumor size and abnormal coagulation factors. PIVKA-II levels were significantly correlated with tumor size (p < 0.0001) and all coagulation factors (p < 0.05) except prothrombin. Hepatic hemangiomas were associated with elevated serum PIVKA-II levels, showing significant correlations with tumor size and coagulation disorders. PIVKA-II elevation was attributed to the increased production of prothrombin precursors caused by accelerated coagulation–fibrinolysis within hemangiomas. Full article

Splanchnic vein thrombosis (SVT), which is particularly prevalent in myeloproliferative neoplasms (MPNs), has a multifactorial pathomechanism involving the anticoagulant protein C (PC) pathway. To better characterize the hypercoagulable state in SVT we assessed its key enzymes thrombin and activated PC (APC). The study population included 73 patients with SVT, thereof 36 MPN+, confirmed by bone marrow biopsy, 37 MPN−, and 30 healthy controls. Direct measurement of the active enzyme forms of thrombin and APC in the circulation was achieved by using oligonucleotide-based enzyme capture assays (OECA). Additionally, activation markers of coagulation and fibrinolysis were measured. Plasma levels of free thrombin and APC were higher in the MPN+ than in the MPN− cohort, with 0.49 vs. <0.46 pmol/L (p = 0.0057), respectively, 1.23 vs. 0.58 pmol/L (p = 0.0122), and in healthy controls (vs. <0.46 pmol/L, p = 0.0012; vs. 0.54 pmol/L, p = 0.0035). The indirect activation markers prothrombin fragment 1+2, thrombin-antithrombin complex, and D-dimer did not differ between groups. Receiver operating characteristic analysis suggested that SVT patients with MPN can be better distinguished by APC than by conventional indirect thrombin markers. A potential application of these biomarkers to guide anticoagulant therapy and to investigate the role of the PC pathway in MPN-associated hypercoagulability should be further studied. Full article

Sepsis-associated coagulopathy increases risk of mortality. Impairment of the anticoagulant protein C (PC) pathway may contribute to the thrombotic phenotype in coronavirus disease 2019 (COVID-19) sepsis. This study assessed the functionality of this pathway in COVID-19 and non-COVID sepsis by measuring its key enzymes, thrombin and activated PC (APC). The study population included 30 patients with COVID-19, 47 patients with non-COVID sepsis, and 40 healthy controls. In healthy controls, coagulation activation and subsequent APC formation was induced by 15 µg/kg recombinant activated factor VII one hour before blood sampling. APC and thrombin in plasma were measured using oligonucleotide-based enzyme capture assays. The indirect thrombin markers prothrombin-fragment 1+2 (F1+2) and thrombin-antithrombin complex (TAT) were also measured. Compared with stimulated healthy controls, median thrombin, F1+2, and TAT levels were higher in patients with COVID-19 (up to 6-fold, p < 2 × 10⁻⁶) and non-COVID sepsis (up to 4.7-fold, p < 0.010). APC levels were 2.4-fold higher in patients with COVID-19 (7.44 pmol/L, p = 0.011) and 3.4-fold higher in non-COVID sepsis patients (10.45 pmol/L, p = 2 × 10⁻⁴) than in controls (3.08 pmol/L). Thrombin markers and APC showed correlation in both COVID-19 (r = 0.364–0.661) and non-COVID sepsis patients (r = 0.535–0.711). After adjustment for PC levels, median APC/thrombin, APC/F1+2, and APC/TAT ratios were 2-fold (p = 0.036), 6-fold (p = 3 × 10⁻⁷) and 3-fold (p = 8 × 10⁻⁴) lower in the COVID-19 group than in the non-COVID sepsis group, and the latter two were also lower in the COVID-19 group than in stimulated healthy controls. In conclusion, it was found that a comparatively lower anticoagulant APC response in COVID-19 patients as compared to non-COVID sepsis patients, potentially linked to endothelial dysfunction, contributes to the prothrombotic phenotype of COVID-19 sepsis. Full article

The advent of intracranial stents has revolutionized the endovascular treatment of cerebral aneurysms. The utilization of stents has rendered numerous cerebral aneurysm amenable to endovascular treatment, thereby obviating the need for otherwise invasive open surgical options. Stent placement has become a mainstream approach because of its safety and efficacy. However, further improvements are required for clinically approved devices to avoid the frequent occurrence of thrombotic complications. Therefore, controlling the thrombotic complications associated with the use of devices is of significant importance. Our group has developed a unique stent coated with a 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer. In this study, the surface characteristics of the polymer coating were verified using X-ray photoelectron spectroscopy and atomic force microscopy. Subsequently, the antithrombotic properties of the coating were evaluated by measuring platelet count and thrombin–antithrombin complex levels of whole human blood after 3 h of incubation in a Chandler loop model. Scanning electron microscopy was utilized to examine thrombus formation on the stent surface. We observed that MPC polymer-coated stents significantly reduced thrombus formation as compared to bare stents and several clinically approved devices. Finally, the coated stents were further analyzed by implanting them in the internal thoracic arteries of pigs. Angiographic imaging and histopathological examinations that were performed one week after implantation revealed that the vascular lumen was well maintained and coated stents were integrated within the vascular endothelium without inducing adverse effects. Thus, we demonstrated the efficacy of MPC polymer coating as a viable strategy for avoiding the thrombotic risks associated with neurovascular stents. Full article

Background/Objectives: The coagulation cascade due to tissue damage is considered to be one of the causes of poor prognostic outcomes in patients with acute exacerbations of interstitial lung disease (AE-ILD). This study aimed to confirm coagulopathy in AE-ILD by evaluating the differences in the clinical characteristics of coagulation/fibrinolysis markers between stable ILD and AE-ILD. Methods: Overall, 81 patients were enrolled in this retrospective study and categorized into the following two groups: a chronic ILD group comprising 63 outpatients and an acute ILD group comprising 18 inpatients diagnosed with AE-ILD. Serum markers, including thrombin–antithrombin III complex (TAT), D-dimer, plasmin–α2 plasmin inhibitor complex (PIC), and surfactant protein D (SP-D), were compared between the groups. Results: Among the 18 patients with acute ILD, 17 did not meet the International Society of Thrombosis and Hemostasis scoring system for disseminated intravascular coagulation. In acute ILD, the SP-D levels were statistically significantly positively correlated with TAT, D-dimer, and PIC levels, while the Krebs von den Lungen 6 (KL-6) levels showed no correlation with any of these coagulation/fibrinolytic markers. A positive correlation was observed between SP-D levels and TAT, D-dimer, and PIC levels in acute ILD. Serum TAT, D-dimer, and PIC all showed good area under the receiver operating characteristic (ROC) curve (AUC) values in ROC analysis for the diagnosis of acute ILD. Conclusions: In the clinical setting of AE-ILD, it may be important to focus not only on alveolar damage markers such as SP-D but also on coagulation/fibrinolytic markers including TAT, D-dimer, and PIC. Full article

During the last two decades, several cases of venous thrombosis (VTE) after a prolonged period at a computer have been described, denominated as “eThrombosis”. Video gaming on a computer has become very popular and can be a social activity where several players gather to play against each other or in a virtual environment for several days (“LAN (i.e., Local Area Network) parties”) where the participants are sedentary and consuming calorie-rich food items. The aim of this study was to investigate potential coagulation activation during a 42 h LAN party. Nine male gamers volunteered for the LAN party. Citrated blood was sampled before and every 6 h, and plasma was analyzed for thrombin generation, thrombin–antithrombin complexes (TAT), prothrombin fragment 1 + 2 (F1 + 2), and D-dimer. Thrombin generation increased slightly but not significantly during the LAN party, whereas the coagulation activation markers were unchanged. These results do not indicate that the coagulation system is activated significantly during 42 h of gaming with minimal physical activity. Although increased activity cannot be excluded, it does not directly indicate a risk of VTE in general. Full article

In short-term diabetes (3 weeks), suramin, a drug used clinically, affects renal function and the expression of vascular endothelial growth factor A (VEGF-A), which may be involved in the pathogenesis of diabetic nephropathy, the main cause of end-stage renal disease. In the present study, we evaluated the long-term (11 weeks) effects of suramin (10 mg/kg, i.p., once-weekly) in diabetic rats. Concentrations of VEGF-A, albumin, soluble adhesive molecules (sICAM-1, sVCAM-1), nucleosomes, and thrombin–antithrombin complex (TAT) were measured by ELISA, total protein was measured using a biuret reagent. Glomerular expression of VEGF-A was evaluated by Western blot, mRNA for VEGF-A receptors in the renal cortex by RT-PCR. The vasoreactivity of the interlobar arteries to acetylcholine was assessed by wire myography. Long-term diabetes led to an increased concentration of VEGF-A, TAT, and urinary excretion of total protein and albumin, and a decrease in the concentration of sVCAM-1. We have shown that suramin in diabetes reduces total urinary protein excretion and restores the relaxing properties of acetylcholine relaxation properties to non-diabetic levels. Suramin had no effect on glomerular expression VEGF-A expression and specific receptors, and on sICAM-1 and nucleosomes concentrations in diabetic rats. In conclusion, the long-term effect of suramin on the kidneys in diabetes, expressed in the reduction of proteinuria and the restoration of endothelium-dependent relaxation of the renal arteries, can be considered as potentially contributing to the reduction/slowing down of the development of diabetic nephropathy. Full article

Food and drinks can be contaminated with pollutants such as lead and strontium, which poses a serious danger to human health. For this reason, a number of effective sensors have been developed for the rapid and highly selective detection of such contaminants. TBA, a well-known aptamer developed to selectively target and thereby inhibit the protein of clinical interest α-thrombin, is receiving increasing attention for sensing applications, particularly for the sensing of different cations. Indeed, TBA, in the presence of these cations, folds into the stable G-quadruplex structure. Furthermore, different cations produce small but significant changes in this structure that result in changes in the electrical responses that TBA can produce. In this article, we give an overview of the expected data regarding the use of TBA in the detection of lead and strontium, calculating the expected electrical response using different measurement techniques. Finally, we conclude that TBA should be able to detect strontium with a sensitivity approximately double that achievable for lead. Full article

Background: Knowledge of the natural history and management of hepatic hemangiomas is lacking. The aim of this study was to investigate the natural history of hemangiomas and to elucidate the factors that determine tumor growth and optimal management. Methods: A total of 211 adult patients were enrolled, with follow-up for more than three years. Follow-up was performed with repeated ultrasonography (US) and laboratory tests for liver function and coagulation factors (platelets, prothrombin time (PT), fibrinogen, thrombin–antithrombin III complex (TAT), D-dimer, and fibrin and fibrinogen degradation products (FDP)). Results: Tumor size decreased in 38.9% of patients, showed no change in 31.3%, and increased in 29.8%. The incidence of a size increase was very high in patients under 40 years of age and decreased gradually with age, whereas the incidence of a size decrease increased with age and increased markedly over 60 years of age. The incidence of an increase in size decreased gradually with size enlargement, whereas the incidence of a decrease in size increased markedly with tumor size and further increased rapidly when hemangiomas became larger than 60 mm. Values of TAT, D-dimer, FDP, and Mac-2 binding protein glycosylation isomer (M2BPGi) were closely related to the change in size of hemangiomas. Conclusions: Hemangiomas in older patients (>60 years of age) and larger tumors (>60 mm in size) had a tendency to decrease in size, resulting from the reduction in coagulation disorders and the progression of liver fibrosis. Therefore, the majority of patients with hemangiomas can be safely managed by clinical observation. Full article

The present study investigated early interactions between three alloplastic materials (calcium phosphate (CaP), titanium alloy (Ti), and polyetheretherketone (PEEK) with human whole blood using an established in vitro slide chamber model. After 60 min of contact with blood, coagulation (thrombin–antithrombin complexes, TAT) was initiated on all test materials (Ti > PEEK > CaP), with a significant increase only for Ti. All materials showed increased contact activation, with the KK–AT complex significantly increasing for CaP (p < 0.001), Ti (p < 0.01), and PEEK (p < 0.01) while only CaP demonstrated a notable rise in KK-C1INH production (p < 0.01). The complement system had significant activation across all materials, with CaP (p < 0.0001, p < 0.0001) generating the most pronounced levels of C3a and sC5b-9, followed by Ti (p < 0.001, p < 0.001) and lastly, PEEK (p < 0.001, p < 0.01). This activation correlated with leukocyte stimulation, particularly myeloperoxidase release. Consequently, the complement system may assume a more significant role in the early stages post implantation in response to CaP materials than previously recognized. Activation of the complement system and the inevitable activation of leukocytes might provide a more favorable environment for tissue remodeling and repair than has been traditionally acknowledged. While these findings are limited to the early blood response, complement and leukocyte activation suggest improved healing outcomes, which may impact long-term clinical outcomes. Full article